Minimal impact access system to disc space

Abstract

Methods and apparatus for accessing and repairing a vertebral disc include a pad with a central cut-out mounted to the skin of a patient or, alternatively, a pedicle-mounted support. An incision is made and then a corridor is created using an elongated guide and a series of dilating tubes. An access to the disc space is created through the superior articular process and the facet joint using the corridor defined by the dilating tubes. Nucleus material is removed from the disc space and the vertebral endplates are prepared. The disc space may be sized to select a suitable implant, which is advanced through the corridor and into the disc space following discectomy and endplate preparation. Bone graft material may be inserted into the disc space following installation of the implant and then posterior rigid fixation may be achieved using percutaneous pedicle screws, followed by closure of the site.

The invention claimed is: 
     
       1. A minimal impact access system for accessing a vertebral disc space comprising:
 a pad configured to be secured to a skin surface of a patient and defining an opening; 
 a retractor frame secured with respect to the pad and defining an opening at least partially aligned with the opening of the pad; 
 a swivel base configured to be secured with respect to the pad and including a swivel at least partially aligned with the openings of the pad and the retractor frame; and 
 an outermost dilating tube received by the swivel for pivotal movement with respect to the pad and defining a corridor for accessing the vertebral disc space of the patient, wherein 
 a position of the swivel base with respect to the pad and to the retractor frame is adjustable prior to the swivel base being secured with respect to the pad, and 
 the retractor frame includes a lever configured to be actuated to produce a sucking action between the pad and the swivel base to releasably secure the swivel base with respect to the pad. 
 
     
     
       2. The minimal impact access system of  claim 1 , further comprising an elongated guide configured to facilitate positioning of the outermost dilating tube with respect to the pad. 
     
     
       3. The minimal impact access system of  claim 2 , further comprising a plurality of inner dilating tubes, wherein
 each inner dilating tube has a different diameter, 
 the diameters of the inner dilating tubes are smaller than a diameter of the outermost dilating tube, and 
 the inner dilating tubes are configured to be sequentially advanced over the elongated guide prior to advancement of the outermost dilating tube over the elongated guide and the inner dilating tubes. 
 
     
     
       4. The minimal impact access system of  claim 1 , wherein the outermost dilating tube comprises a distal end including at least one impaction tooth or anchoring spike. 
     
     
       5. The minimal impact access system of  claim 1 , wherein the elongated guide comprises an osteotome. 
     
     
       6. The minimal impact access system of  claim 1 , wherein the elongated guide comprises a metallic pin including a threaded distal tip. 
     
     
       7. The minimal impact access system of  claim 1 , wherein the pad comprises a gel pad including an adhesive backing. 
     
     
       8. A minimal impact access system for accessing a vertebral disc space comprising:
 a pad configured to be secured to a skin surface of a patient and defining an opening; 
 a retractor frame secured with respect to the pad and defining an opening at least partially aligned with the opening of the pad; 
 a swivel base including a swivel at least partially aligned with the openings of the pad and the retractor frame; 
 a clamping ring plate secured over the swivel base to secure the swivel base with respect to the pad; and 
 an outermost dilating tube received by the swivel for pivotal movement with respect to the pad and defining a corridor for accessing the vertebral disc space of the patient, wherein a position of the swivel base with respect to the pad and to the retractor frame is adjustable prior to the swivel base being secured with respect to the pad. 
 
     
     
       9. A method for accessing a vertebral disc space comprising:
 applying a pad to a skin surface of a patient, the pad defining an opening; 
 creating an access in the skin surface within the opening; 
 advancing an elongated guide through the access to a target location; 
 advancing an outermost dilating tube over the elongated guide; 
 advancing a retractor frame and a swivel base over the outermost dilating tube, the retractor frame defining an opening at least partially aligned with the opening of the pad and the swivel base including a swivel at least partially aligned with the openings of the pad and the retractor frame; 
 securing the retractor frame and the swivel base with respect to the pad; and 
 creating an access into the vertebral disc space through the outermost dilating tube, wherein a position of the swivel base with respect to the pad and to the retractor frame is adjusted prior to securing the swivel base with respect to the pad. 
 
     
     
       10. The method of  claim 9 , wherein the target location comprises a facet joint. 
     
     
       11. The method of  claim 9 , wherein the target location comprises a superficial aspect of a joint line. 
     
     
       12. The method of  claim 9 , wherein the target location comprises a vertebral disc. 
     
     
       13. The method of  claim 9 , wherein the guide is advanced to the target location via Kambin's triangle. 
     
     
       14. The method of  claim 9 , further comprising
 advancing a plurality of inner dilating tubes of successively increasing diameter over the elongated guide, wherein said advancing the outermost dilating tube over the elongated guide includes advancing the outermost dilating tube over the inner dilating tubes, and 
 removing said plurality of inner dilating tubes prior to said creating the access into the vertebral disc space through the outermost dilating tube. 
 
     
     
       15. The method of  claim 9 , further comprising adjusting an angle of the outermost dilating tube with respect to the pad after said securing the retractor frame and the swivel base with respect to the pad. 
     
     
       16. The method of  claim 9 , wherein said advancing the outermost dilating tube over the elongated guide includes advancing at least one impaction tooth or anchoring spike at a distal end of the outermost dilating tube into the target location. 
     
     
       17. The method of  claim 9 , further comprising advancing a clamping ring plate over the elongated guide and over the swivel base to secure the swivel base with respect to the pad. 
     
     
       18. The method of  claim 9 , further comprising actuating a lever of the retractor frame to produce a sucking action between the pad and the swivel base to releasably secure the swivel base with respect to the pad. 
     
     
       19. The method of  claim 9 , further comprising adjusting a position of the outermost dilating tube with respect to the pad in a plane defined by the pad.